The present invention generally relates to a key-lock arrangement and more particularly, to a key-lock system to be employed in an IC card provided with a display portion or the like.
By way of example, there is conventionally available an IC card with a display portion capable of inhibiting input (referred to as key-lock hereinafter) from a keyboard as shown in FIG. 5. The known IC card 1 is provided, in its keyboard 2, with a "LOCK" key 3 and a "LOCK RELEASE" key 4. The "LOCK" key 3 is a key for effecting the key-lock, while the "LOCK RELEASE" key is a key for releasing the inhibition of input (referred to as lock release hereinafter) from the keyboard. Thus, the key-lock is effected by depressing the "LOCK" key 3, and the lock release is effected by depressing said "LOCK RELEASE" key 4. A display portion 5 is provided for displaying contents of input from the keyboard 2, etc. or results of calculation and the like.
However, since the key-lock system employed in the above conventional IC card 1 is arranged to effect the key-lock by depressing the "LOCK" key 3, and the lock release by depressing the "LOCK RELEASE" key 4, there are problems as described hereinafter.
More specifically, in the IC card 1 as referred to above, in the case where automatic payment or the like is to be effected by an automatic teller machine (referred to as ATM hereinafter), said IC card 1 is adapted to be fed into the ATM by a rotating roller (not shown). Meanwhile, when an embossed code formed by embossment 6 on the surface of the IC card 1 is to be transferred onto a slip 7 or the like by an imprinter, as shown in FIG. 6, the slip 7 placed on the surface of the IC card 1 formed with the embossed code is depressed by an imprinter roller 8, whereby the embossment 6 which constitutes the embossed code on the surface of said IC card 1 is transferred onto the slip 7.
Accordingly, there are cases where even when the key-lock has been effected through depression of the "LOCK" key 3, since the surface of the IC card 1 is depressed by the rotating roller 8 during feeding of the IC card 1 into the ATM or during transfer of the embossed code by the imprinter roller 8, the "LOCK RELEASE" key 4 provided on the reverse surface of the card 1 is depressed by the roller 8, thus the key-lock being undesirably released. Furthermore, in the case as described above, if the roller 8 further proceeds from the position of the "LOCK RELEASE" key 4, and depresses other numerical keys, such depressed keys are undesirably inputted, thus resulting in erroneous functions.